ElBaradei also was given new information on Iran's "new generation of centrifuges" during weekend talks with Iranian leaders, said his spokeswoman, Melissa Fleming. That issue is a priority for the agency as it tries to establish how far advanced Iran is in developing the technology.

Announcing the deadline, Fleming spoke only in general terms, without mentioning what was being now probed by agency experts under a plan agreed to last summer. But diplomats said that investigation was now in its final stage, focusing on programs with possible weapons applications.

... Separately, however, a senior diplomat expressed doubt ElBaradei was able to persuade the Iranians to freeze enrichment and noted Western efforts for additional U.N. sanctions against the Islamic republic would continue unless that condition was met. Both spoke on condition of anonymity because they were not authorized to comment publicly on the issue.

Following the talks, Iran wants the Security Council to hand its nuclear case back to the IAEA, reports Iranian Press TV.

While Iran has addressed queries about its nuclear activities in the past, including explanations for its plutonium experiments, it has yet to address questions about its current activities, reports Reuters. "The IAEA wants Iran to observe its additional protocol, which permits short-notice inspections at locations beyond declared nuclear sites.... Without it, the IAEA cannot verify that Iran's nuclear work is wholly peaceful."

The announcement essentially delayed for another month what had been an end-of-the-year deadline to disclose all of its nuclear work, including any covert or undeclared military research.

Over the past year and a half the Iranians have repeatedly made declarations that they would answer outstanding questions within a week, but each of those deadlines has passed with only partial answers offered.

Meanwhile, President Bush continued to criticize Iran about its purported nuclear ambitions, saying on Sunday from Abu Dhabi that Tehran "defies the UN and destabilises the region by refusing to be open and transparent about its nuclear programs and ambitions," reports Al Jazeera.

Calling Iran the "world's leading state sponsor of terror", he urged Arab states to join with the US to confront the danger "before it's too late".

Israel's prime minister Ehud Olmert said Monday that Israel would reject " 'no options' to block Iran from obtaining nuclear weapons." That may be the clearest indication yet that Mr. Olmert is willing to use military force against Iran, reports the Associated Press.

Just before President Bush arrived in Saudi Arabia, a leading Saudi newspaper "ruled out any attempt by the United States to use the oil-rich Gulf kingdom as a launchpad for a possible war on Iran over Tehran's disputed nuclear programme," reports Agence France-Presse.

"This issue can be solved through diplomatic means and through dialogue," said the paper, which reflects the views of the Saudi authorities.

Bush on Friday began a four-nation Gulf tour as part of a Middle East trip to push for a peace deal between Israel and the Palestinians and to rally the support of his allies in the Sunni Muslim oil monarchies against the "threat" he says is posed by Shiite Muslim Iran.